I've used LMDE (64bit, kernel 3.0.0-1) with Xfce desktop on my laptop computer for a while. I've noticed that the Xfce terminal (version 0.4.8 ) is often laggy and unresponsive. Running simple commands may take several seconds and even typing and navigating in a text mode program (let's say, vim) is sometimes affected.

I haven't noticed such lag on Mandriva with KDE desktop and Konsole terminal.